prefrontal cortex – The Miller Lab

14

Aug 2018

Structuring of Abstract Working Memory Content by Fronto-parietal Synchrony in Primate Cortex

Miller Lab

Neuroscience

Super-cool paper by Andreas Nieder and crew. Frontal-parietal beta synchrony encodes the most recent numerical input. Theta synchrony distinguishes between different numerosities held in working memory. The spiking of mixed-selectivity neurons multiplexed both task-relevant and irrelevant stimuli but they were separated in different phases of theta oscillations. Powerful support that neural oscillations functionally organize spiking activty.

Jacob, S. N., Hähnke, D., & Nieder, A. (2018). Structuring of Abstract Working Memory Content by Fronto-parietal Synchrony in Primate Cortex. Neuron, 99(3), 588-597.
3

Jul 2018

Coordinated prefrontal–hippocampal activity and navigation strategy-related prefrontal firing during spatial memory formation

Miller Lab

Neuroscience

Enhanced prefrontal-hippocampal spike-LFP coupling during learning of a spatial strategy (but not other strategies).

Negrón-Oyarzo, I., Espinosa, N., Aguilar, M., Fuenzalida, M., Aboitiz, F., & Fuentealba, P. (2018). Coordinated prefrontal–hippocampal activity and navigation strategy-related prefrontal firing during spatial memory formation. Proceedings of the National Academy of Sciences, 201720117.
19

Mar 2018

Attentional Changes in Either Criterion or Sensitivity Are Associated with Robust Modulations in Lateral Prefrontal Cortex

Miller Lab

Neuroscience

The effects of attention in the brain can be partitioned into changes in sensitivity of in the subject’s criterion. In visual cortex, only changes in sensitivity are seen. Here, Luo and Maunsell show that neurons in frontal cortex are sensitive to changes in sensitivity as well as criterion.

Luo, T. Z., & Maunsell, J. H. (2018). Attentional Changes in Either Criterion or Sensitivity Are Associated with Robust Modulations in Lateral Prefrontal Cortex. Neuron.
12

Mar 2018

Frontal cortex function as derived from hierarchical predictive coding

Miller Lab

Neuroscience

Alexander and Brown show how frontal lobe function can be explained by a hierarchical stack of a computational motif based on predictive coding.

Alexander, W. H., & Brown, J. W. (2018). Frontal cortex function as derived from hierarchical predictive coding. Scientific reports, 8(1), 3843.
26

Feb 2018

Dissonant Representations of Visual Space in Prefrontal Cortex during Eye Movements

Miller Lab

Neuroscience

Interesting new study from the Moore Lab showing how spatial information is evident in different frequency bands in the prefrontal cortex. They also show a dissociation between high gamma/spiking and alpha.

Chen, X., Zirnsak, M., & Moore, T. (2018). Dissonant Representations of Visual Space in Prefrontal Cortex during Eye Movements. Cell Reports, 22(8), 2039-2052.
25

Jan 2018

New paper: Different Levels of Category Abstraction by Different Dynamics in Different Prefrontal Areas

Miller Lab

Miller Laboratory, Neuroscience

Wutz, A., Loonis, R., Roy, J.E., Donoghue, J.A., and Miller, E.K. (2018) Different levels of category abstraction by different dynamics in different prefrontal areas. Neuron published online Jan 25 2018.

SUMMARY

Categories can be grouped by shared sensory attributes (i.e. cats) or by a more abstract rule (i.e. animals). We explored the neural basis of abstraction by recording from multi-electrode arrays in prefrontal cortex (PFC) while monkeys performed a dot-pattern categorization task. Category abstraction was varied by the degree of exemplar distortion from the prototype pattern. Different dynamics in different PFC regions processed different levels of category abstraction. Bottom-up dynamics (stimulus-locked gamma power and spiking) in ventral PFC processed more low-level abstractions whereas top-down dynamics (beta power and beta spike-LFP coherence) in dorsal PFC processed more high-level abstractions. Our results suggest a two-stage, rhythm-based model for abstracting categories.
9

Jan 2018

Electrical stimulation of macaque lateral prefrontal cortex modulates oculomotor behavior indicative of a disruption of top-down attention

Miller Lab

Neuroscience

The authors report different effects of stimulation of the lateral prefrontal cortex. Stimulation at or near the FEF prolonged or decreased saccade reaction time, depending on task instructions. More rostral stimulation affected the attention weighting of saccade targets.

Schwedhelm, P., Baldauf, D., & Treue, S. (2017). Electrical stimulation of macaque lateral prefrontal cortex modulates oculomotor behavior indicative of a disruption of top-down attention. Scientific reports, 7(1), 17715.
5

Dec 2017

Contributions of primate prefrontal cortex and medial temporal lobe to temporal-order memory

Miller Lab

Neuroscience

An interesting contrast between the prefrontal cortex (PFC) and medial temporal lobe (MTL) in encoding temporal order. PFC neurons showed stronger “mixed selectivity” type encoding. They responded to a combination of an item and the order in which in appeared, only responding to specific items at specific times. By contrast, MTL neurons were mainly item-selective. They typically responded to an item, regardless of its order, but their firing rate was modulated by order.

Naya, Y., Chen, H., Yang, C., & Suzuki, W. A. (2017). Contributions of primate prefrontal cortex and medial temporal lobe to temporal-order memory. Proceedings of the National Academy of Sciences, 201712711.

Further reading on mixed selectivity:
Rigotti, M., Barak, O., Warden, M.R., Wang, X., Daw, N.D., Miller, E.K., & Fusi, S. (2013) The importance of mixed selectivity in complex cognitive tasks. Nature, 497, 585-590, doi:10.1038/nature12160. View PDF »

Fusi, S., Miller, E.K., and Rigotti, M. (2016) Why neurons mix: High dimensionality for higher cognition. Current Opinion in Neurobiology. 37:66-74 doi:10.1016/j.conb.2016.01.010. View PDF »
31

Oct 2017

What constitutes the prefrontal cortex?

Miller Lab

Neuroscience

Do rodents have one? The answer is not straightforward. Marie Carlén reviews the data for us.

Carlén, M. (2017). What constitutes the prefrontal cortex?. Science, 358(6362), 478-482.
11

Oct 2017

New Paper: Hebbian Learning in a Random Network Captures Selectivity Properties of Prefrontal Cortex

Miller Lab

Miller Laboratory, Neuroscience

Lindsay, G.W., Rigotti, M., Warden, M.R., Miller, E.K., and Fusi, S. (2017) Hebbian Learning in a Random Network Captures Selectivity Properties of Prefrontal Cortex. Journal of Neuroscience. 6 October 2017, 1222-17; DOI: https://doi.org/10.1523/JNEUROSCI.1222-17.2017 View PDF